.. Flashcards
Voltage and current are measured in practice using
instruments
voltmeters and ammeters
Uses a graduated scale with a
moving pointer to display readings
Analog meter
Provides a reading in numbers and
More accurate than analog meters
Digital meter
used by manually adjusting
and
switching
between
different ranges of a specific
quantity to get most accurate
reading.
Switched Type Multimeter
automatically
adjusting between ranges
of specific parameter or
quantity under test for best
reading.
Auto Range
Type
Multimeter
terminal
to
use
to
measure voltage and
resistance.
Terminal VΩ
terminal
A is used for
current
measurement
the common terminal for
all
measurements
COM
terminal
comes from the word circle. ____ is a collection of real components, power
sources, and signal sources, all connected so
current can flow in a complete circle
Circuit
If the circle
is complete, if all currents have a path back to
where they came from.
Indicates low resistance
Closed circuit
if the circle is not
complete, if there is a gap or opening in the path.
This Indicates high resistance
OPEN CIRCUIT
happens when a path of low resistance (ideally zero) is connected (usually
by mistake) to a component.
Zero ohms of resistance
SHORT CIRCUIT
VOM
VOLT-OHM-MILLIAMMETER
DMM
Digital meter
When measuring the current it is important to never place
the probes directly on the two battery terminals. This will
cause a ____
short circuit
Connect the _____ to the appropriate
current port either “A” or “mA”.
red probe
an instrument which is normally part of a
multimeter together with a voltmeter and an ammeter,
and is used to measure the resistance of a component. It
should be placed across the component under test to
measure the resistance of an isolated component or
circuit.
ohmmeter
Born in Prussia (now Russia), Kirchhoff developed his “laws” while a student in 1845.
Gustav Robert Kirchhoff
These laws allowed him to calculate the voltages and currents in multiple loop circuits.
Kirchhoff’s Law
The algebraic sum of the voltages around any loop is zero. In any closed loop in a network, the algebraic sum of the voltage drops (i.e. products of current and resistance) taken around the loop is equal to the resultant e.m.f. acting in that loop.
KIRCHHOFF’SVOLTAGE LAW( KVL)
Kirchhoff’s first law is based on the law of conservation of charge. Kirchhoff’s current law (KCL) states that the algebraic sum of currents entering a node (or a closed boundary) is zero.
KIRCHHOFF’S CURRENT LAW( KCL)
